Reference is made to application Ser. No. 09/442,559, entitled METHOD AND SYSTEM FOR DIRECTING AN ITEM THROUGH THE FEED PATH OF A FOLDING APPARATUS, assigned to the assignee of this application and filed on even date herewith.
Reference is made to application Ser. No. 09/442,561, entitled METHOD AND SYSTEM FOR FOLDING AND TABBING SHEETS, assigned to the assignee of this application and filed on even date herewith.
Reference is made to U.S. Pat. No. 6,206,817, entitled METHOD AND APPARATUS FOR FOLDING SHEETS, assigned to the assignee of this application and filed on even date herewith.
The present invention relates to a tabber, or an apparatus for sealing a piece of folded material with one or more adhesive tabs.
A self-mailer is conventionally defined as a mailpiece without an envelope. The mailer contains one or more sheets of printed material, folded once or twice by a folding device into a smaller piece for mailing. The folded material has a folded end and an open end. The open end is usually sealed with one or more tabs before the self-mailer is sent to an addressee. In addition, it may be necessary to apply or print an address label and a postage stamp or indicia on the mailpiece for mailing.
Self-mailers are well-known in the art. For example, U.S. Pat. No. 5,711,846 (Alicea) discloses a self-mailing apparatus in which a feeder module is used to feed the folded material, a labeling mechanism is used to apply an address label on each self-mailer and a tabbing device is then used to put a tab on the open end of the folded material. Typically, the tabs that are used to seal the folded material are precut into individual pieces and arranged in a roll on a narrow strip of removable backing material. The removable backing material is also known as the release liner which is used to transport the tabs into position. The adhesive on the tabs can be on the side of the tab that faces the backing material or on the opposite side. As disclosed in U.S. Pat. No. 5,711,846, for the tabs that have adhesive facing the backing material, the tab must be partially separated from the backing material and the backing material be pulled away to expose the adhesive side of the tab in order for the tab to contact the open end of the folded material. In the tabbing process, folded material is transported from an upstream direction, one piece at a time, into the tabbing area where the tab is applied to the edge of the folded material. As the folded material is moving further toward the downstream direction, the tab is caused to adhere to and fold across the edge for securing the folded material. If the adhesive on the tab is on the side that is facing away from the backing material, then the backing material does not need to be partially peeled off to expose the adhesive before the tab is in contact with the folded material. However, after folded material is caused to move into the tabbing area to be sealed with the tab, it is moved back out of the tabbing area in the opposite direction, as disclosed in U.S. Pat. No. 5,279,698 (Davis).
The major disadvantage of the tabbing apparatus that uses precut tabs is that it must be equipped with means for placing the tab correctly in relation to the leading edge of the folded material. As disclosed in U.S. Pat. No. 5,711,846, a pair of optical sensors are used to detect the presence of a tab at the correct location by sensing an ink mark on the tab. Alternatively, a mechanical device including gears and sprockets is used to advance a predetermined amount of backing material in order to place a tab in the tabbing area. Such a mechanical device has been disclosed in U.S. Pat. No. 5,279,698 (Davis). Even with such a mechanical device, one must still have a monitoring device to ascertain that no error, accumulative or otherwise, occurs in the tab positioning.
It is advantageous and desirable to provide a method and an apparatus for tabbing a piece of folded material wherein the tabs are not precut and, therefore, there is no need for having a sensor or a mechanical device to ensure that the tab is positioned correctly over the edge of the folded material. Furthermore, it is desirable to provide a method and an apparatus for tabbing folded material wherein the tabs are not affixed to a removable backing material, thereby reducing the cost of the tabbing material.
The present invention provides an apparatus and a method for tabbing a piece of folded material incoming along a substantially horizontal traveling path from an upstream direction, wherein the folded material has a leading edge, a width, a lower side and an upper side, and wherein the tabbing assembly has a width. The apparatus comprises at least one tape feeder movably mounted on the tabbing assembly along the width thereof in order to seal the leading edge of the folded material at at least one tabbing location, wherein the tape feeder includes a roll of tape having a width, an adhesive side and an opposing non-adhesive side; a transporting mechanism for advancing the tape in order to release a section of the tape from above the traveling path of the folded material into the traveling path with the adhesive side facing the leading edge of the folded material, wherein the released section of the tape has a leading end and a trailing end such that the leading end extends below the traveling path and the trailing end is positioned above the traveling path, and wherein the released section of the tape is placed such that the width of the tape is substantially parallel to the leading edge of the folded material; and a cutting device placed adjacent to the non-adhesive side of the tape and above the released section of the tape. The apparatus further comprises a transport mechanism to move the folded material further downstream so as to cause the released section of the tape to contact with, adhere to and move downstream along with the leading edge of the folded material, wherein the moving of the released section of the tape downstream causes the released section of the tape to be separated from the respective roll of tape by the cutting device, thereby producing a tab adhering to the leading edge of the folded material; and a pressing mechanism to press the tab across the leading edge onto the upper side and lower side of the folded material.
Accordingly, the method of sealing a piece of the folded material at at least one tabbing location comprises the steps of: 1) providing for each tabbing location a roll of adhesive tape having an adhesive side and an opposing non-adhesive side; 2) advancing the tape from above the traveling path of the folded material so that a fixed length of the tape is released into the traveling path with the adhesive side facing the leading edge of the folded material, wherein the released fixed length of the tape is partially positioned below the traveling path and partially positioned above the traveling path; 3) moving the folded material further downstream along the traveling path so as to cause the leading edge of the folded material to contact the released fixed length of the tape; 4) separating the released fixed length of the tape from the roll of tape thereby producing a tab in order to allow the tab to move along with the leading edge of folded material downstream; and 5) pressing the tab from the non-adhesive side so as to provide a good contact between the tab and the folded material across the leading edge of the folded material. For a fuller understanding of nature and objects of the present invention, reference is made to the following description taken in conjunction with FIG. 1 through FIG. 7B.